For classes that only have static methods, consider making them utility classes.
Note that this doesn't apply to abstract classes, since their subclasses may well include non-static methods.
Also, if you want this class to be a utility class, remember to add a private constructor to prevent instantiation.
(Note, that this use was known before PMD 5.1.0 as UseSingleton).

<p>
  This rule is deprecated, use {rule:squid:S1118} instead.
</p>
